EU heads of state and government are expected to confirm former Luxembourg prime minister Jean-Claude Juncker as the next president at this week's European summit meeting in Brussels.
The decision will come despite strong opposition from UK prime minister David Cameron. He believes Juncker is too much in favour of closer political union and might block attempts by the UK government at EU reform.
However, as the 28 leaders concluded their first of two days of talks on Thursday, the majority appeared to be supportive of Juncker's bid to replace current commission president José Manuel Barroso.
"They are contemplating choosing someone who I think will struggle to be voice of reform and change in Europe" - David Cameron
The UK Conservative leader said, "the odds are stacked against me", but warned of "consequences" if Juncker is endorsed. The prime minister declared that EU leaders were wrong to support Juncker. "This is the wrong person, the wrong approach, the wrong principle," he said.
"My message to my fellow heads of government and heads of state is that this approach that they are contemplating taking is the wrong approach for Europe. That is a mistake."
"They are contemplating choosing someone who I think will struggle to be voice of reform and change in Europe," he added.
Germany and France shrugged off British pressure to call a vote on the nomination. But the leaders of Germany and France made it plain that they were prepared to win a vote if Cameron insisted.
While emphasising that the decision on Juncker would be taken on Friday, Angela Merkel offered the UK leader a consolation prize, stressing that she sought to reach "good compromises" on his reform agenda for the next five years.
"There are times when Europe has to say what it wants" - François Hollande
"If we have clarity on the necessary content for the next five years, we will take the decision on the next European commission president," said the German chancellor. "We can find good compromises with Great Britain and move a bit towards Great Britain."
Meanwhile, the French president, François Hollande, said, "If there is British request on this topic, I am for a vote".
"There are times when Europe has to say what it wants."
In a speech delivered to the European council, acting parliament president Gianni Pittella called on EU leaders to support Junker's candidacy, saying, "The process of lead candidates has deepened a European-wide debate about European issues. And without doubt, via this process the European Union has become closer to its citizens, more transparent and more democratic".
"Together, the voters, the European parliament, the political parties, and the heads of government, have opened a new chapter in the history of our union."
"Those who want to lightly do away with this historic achievement, I can only warn: you can't simply say to the people for the first time the commission president will be the result of a democratic vote, you will get to choose who leads the European executive and then ignore their choice."
The Italian deputy added, "Should the will of the voters be disregarded so blatantly, it should come as no surprise to anyone if people turned their back on Europe for good."
S&D group president, Martin Schulz described the move to elect Junker as a "historic step".
"It is EU citizens, not the heads of state and government who have the final say on who leads Europe."
"As we have made clear in previous statements, given the outcome of the European parliament elections we fully support Jean-Claude Juncker. This is what the majority of European citizens have voted for and this is what they should see happen, as a sign that their votes have been respected."
However, the German Socialist warned that, "Any EU commission president candidate who appears before the parliament to ask for our votes will only be supported by our group if they respect our programme for change".
"This includes, among other issues, a fundamental policy shift to end the austerity-only policy ruling in Europe; investment in growth and jobs; and a special focus on the fight against the dramatically high levels of youth unemployment."
Under article 17 of the Lisbon treaty, leaders must take "into account the elections to the European parliament" when nominating the commission chief, with the candidate to be confirmed by the "European parliament by a majority of its component members" next month.